The occasion of this intellectual waywardness may be slighter still. I gaze on the Palatine Hill, or on the Parthenon, or on the Pyramids, which I have read of from a boy, or upon the matter-of-fact reality of the sacred places in the Holy Land, and I have to force my imagination to follow the guidance of sight and of reason. It is to me so strange that a lifelong belief should be changed into sight, and things should be so near me, which hitherto had been visions. And so in times, first of suspense, then of joy; “When the Lord turned the captivity of Sion, then” (according to the Hebrew text) “we were like unto them that dream.” Yet it was a dream which they were certain was a truth, while they seemed to doubt it. So, too, was it in some sense with the Apostles after our Lord’s resurrection. Such vague thoughts, haunting or evanescent, are in no sense akin to that struggle between faith and unbelief, which made the poor father cry out, “I believe, help Thou mine unbelief!” Nay, even what in some minds seems like an undercurrent of scepticism, or a faith founded on a perilous substratum of doubt, need not be more than a temptation, though robbing Certitude of its normal peacefulness. In such a case, faith may still express the steady conviction of the intellect; it may still be the grave, deep, calm, prudent assurance of mature experience, though it is not the ready and impetuous assent of the young, the generous, or the unreflecting. 4. There is another characteristic of Certitude, in contrast with Assent, which it is important to insist upon, and that is, its persistence. Assents may and do change; certitudes endure. This is why religion demands more than an assent to its truth; it requires a certitude, or at least an assent which is convertible into certitude on demand. Without certitude in religious faith there may be much decency of profession and of observance, but there can be no habit of prayer, no directness of devotion, no intercourse with the unseen, no generosity of self-sacrifice. Certitude then is essential to the Christian; and if he is to persevere to the end, his certitude must include in it a principle of persistence. This it has; as I shall explain in the next Section. § 2. Indefectibility of Certitude.